Thermal gelation of globulin from Phaseolus angularis (red bean)

The heat-induced gelation properties of red bean globulin (RBG) were studied under the influence of salts and several protein structure perturbants. The viscoelastic properties of the gels were evaluated by small amplitude oscillatory tests and creep experiments. Gel structure developed progressively when a protein dispersion (≈10% w/v) was heated from 25 to 95 °C, and both the storage modulus (G′) and loss modulus (G″) increased rapidly during cooling. The addition of NaCl at lower concentrations led to increases in G′ and G″ values, with decreased creep compliance, suggesting higher viscoelasticity. At higher salt concentrations, viscoelasticity was decreased, and the optimum NaCl concentration to produce maximum gel rigidity was 0.2 M. Sodium dodecyl sulfate and urea caused more pronounced reduction of the gel moduli than dithiothreitol and N-ethylmaleimide. The data suggest that hydrophobic interactions and hydrogen bonding play an important role in heat-induced gelation, while electrostatic interactions and a balance of attractive–repulsive forces are also important. The gels formed at 95 °C exhibited a homogenous microstructure with extensive cross-links and sheet-like network structures.     

阳泉矿区综放工作面瓦斯综合治理探讨

充分发挥综采放顶煤开采的技术优势,治理综放工作面瓦斯尤为重要。在介绍阳泉矿区15号煤层及邻近煤岩层瓦斯赋存基础上,分析了综放工作面瓦斯来源和特征,提出了不同条件下瓦斯治理方法及治理措施,并对其治理效果进行了分析。实践应用表明,走向高抽巷与内错尾巷共用系统排放工作面瓦斯,效果最为显著。     

Amorphous CoFeP/NC hybrids as highly efficient electrocatalysts for water oxidation

The rational design and regulate structure and composition are pivotal for the development of highly efficient oxygen evolution reaction (OER) catalysts for water splitting. In this study, amorphous CoFeP/NC hybrid electrocatalyst has been synthesized by a simple and effective phosphorization of a CoFe-based coordination polymer under N₂ atmosphere. The synergistic effects between the CoFeP and N-doped carbon has led to high electronic conductivity attributed to the optimal Fe contents with N-doped carbon and enlarged electrocatalytic active surface area aroused by the nanostructure of CoFeP/NC, as well as the surface structural evolution of oxyhydroxide/phosphate during OER process. The resulting Co_0.35Fe_0.17P_0.48/NC electrocatalyst can attain a current density of 10 mA/cm² at an overpotential of 275 mV with a Tafel slope of 31 mV/dec on glassy carbon electrode and 228 mV on Ni foam electrode in 1 M KOH solution, long-term OER stability of this Co_0.35Fe_0.17P_0.48/NC under the applied potential of 1.53 V vs. RHE demonstrates no obvious decline in current densities of 110 mA/cm² within 17 h, which outperforms those of the contrast electrocatalysts in this work and also comparable to that of many of the reported electrocatalysts in the literatures. This Co_0.35Fe_0.17P_0.48/NC electrocatalyst highlights the rational modulation of optimal composition and electronic structure with homogeneous incorporation of the foreign metal-doped and N-doped carbon for the synthesis of highly efficient electrocatalysts toward to the water oxidation reactions.     

最小二乘意义下主客观评价一致的电能质量综合评估

综合考虑不同专家对电能质量指标重要程度的偏好差异以及负荷对指标的敏感度不同,提出了基于最小二乘意义下主客观评价一致的电能质量综合评估方法。首先利用层次分析法进行主观赋权,再根据评价指标在不同被评价对象中的差异,采用变异系数法得到反映指标客观特性的权重系数,最后基于最小二乘法求得综合反映主客观的权重系数。定义了电力系统标准电压,用此组合权重并基于灰色关联分析法,计算待评估电压与标准电压的关联度,并将其进行等级划分。在PSCAD环境下搭建了系统模型,基于MATLAB编写相应的电能质量评估程序,对两个不同电压等级的4条母线电压进行了综合评估,并与木桶原理方法得到的评估结果进行了比较,证明了该方法的合理性和实用性。     

厚度对掺铝氧化锌透明导电薄膜性质的影响

采用紫外光助溶胶一凝胶法在玻璃基底上制备了掺铝氧化锌薄膜。研究了厚度对薄膜性质的影响,结果表明：所有薄膜均由具有c轴优先生长取向的六角纤锌矿结构的ZnO晶体构成,晶体的粒径随厚度的增加而先增大,达到最大值后,不再随厚度的增加而改变;薄膜的方阻随厚度的增加先减小,在达刮最小值2．1×10^2Ω／口后,随厚度的增加又略有增大;而所有薄膜均是透明的,在可见光区的透光率〉80％。     

电催化二氧化碳还原制乙烯铜基催化剂研究进展

由太阳能、风能驱动CO₂电化学还原为高附加值的燃料和化学品是缓解温室效应和实现碳减排的方法。铜基催化剂作为CO₂还原为碳氢化合物的催化剂受到广泛的关注,但反应过电位高、目标产物选择性低和催化剂稳定性差等仍是开发铜基催化剂需解决的问题和面临的挑战。简述了电催化还原CO₂为乙烯的反应机理,总结了最近铜基催化剂形貌和晶面调控、缺陷构造、杂原子掺杂以及双金属合金化对其性能影响的研究进展,为电催化CO₂还原制乙烯高效催化剂的研发提供参考。     

基于突变理论电网企业信息安全风险管理模型研究

当代信息技术的快速发展使得电网企业面临着更为错综复杂的信息安全威胁,信息安全风险管理的作用也显得更加重要。因此,结合电网企业的特性,针对其信息安全风险管理进行了深入的研究与分析。首先,结合电网企业内外部信息环境的特点,对信息安全的风险进行了科学合理的归类识别;其次,首次结合突变理论构建信息安全风险评估模型,并结合其风险评估的结果设定阈值制定了风险应对的措施;此外,为增加电网企业信息安全的稳定性和可靠性,提出了多维度和多层次的风险防范措施;最后,通过将其方法应用到电网企业信息安全风险管理的实例验证了该方法的有效性和合理性。     

醋醅中不同的含水量对山西老陈醋熏醅品质的影响

通过对比含水量为60%、50%和40%的醋醅在熏醅前后的变化,分析醋醅不同含水量对总酸、蛋白质、不挥发酸、氨基酸态氮、还原糖、总酯、淀粉、总黄酮及丙二醛等的影响。结果表明,氨基酸态氮和淀粉在含水量40%的醋醅中含量降低速度最快,熏醅第1天分别由0.49%和10.00%降低至0.13%和4.75%,含水量50%的醋醅次之,分别降至0.34%和7.49%;还原糖在含水量50%的醋醅中含量降低速度最快,熏醅第1天由4.50%降至1.67%;含水量60%和50%的醋醅更有利于酯类和黄酮类成分的保留,其中酯类由1.70%分别升高至3.42%和3.78%,总黄酮由7.77 mg/100 g分别升高至9.93 mg/100 g和12.10 mg/100 g。丙二醛生成量在含水量60%、50%和40%醋醅中分别达到0.41 mg/kg、0.74 mg/kg和1.14 mg/kg。在3种不同含水量的醋醅中,含水量50%的醋醅中各类物质的变化最为均衡。     

基于模拟胃消化对小米黄酒抗氧化活性的影响

为了探究小米黄酒在模拟胃消化前后抗氧化活性的变化规律,以小米黄酒为材料,采用体外模拟胃消化方法,分别以三种自由基清除率评价消化前后的抗氧化活性。结果表明：经过模拟胃消化2 h后,小米黄酒的1,1-二苯基-2-苦基苯肼自由基（DPPH·）清除率、羟自由基（·OH）清除率、超氧阴离子自由基（O2-·）清除率和还原能力（OD700 nm值）分别为88.90%、78.91%、78.67%和0.309;对比模拟胃消化0 h时,分别提高了76.87%、57.92%、68.43%和0.223。经过模拟胃消化后的小米黄酒,在消化液浓度范围内的抗氧化活性明显提高,表明小米黄酒具有较强的抗氧化活性。